Sleepy Eye Lake Water Temperature
Sleepy Eye Lake in Brown County, Minnesota typically sits around 69°F at the surface in September — warmest in Jul (~81°F) and coldest in Oct (~52°F). That is a typical value for the month, not a live reading.
Typical water temperature by month
Typical surface water temperature by month, from 96 field readings (2017–2023) via the EPA Water Quality Portal. Months with too few readings are left blank.
Is Sleepy Eye Lake warm enough to swim?
Pleasant for swimming — the range most people find enjoyable without a wetsuit.
Want more than temperature? Sleepy Eye Lake scored C on water quality — clarity, algae, phosphorus, depth, fish species, and swimming safety, all on one report card.
Water temperatures at nearby Minnesota lakes
Summer average ~77°F
Summer average ~77°F
Summer average ~77°F
Summer average ~77°F
Summer average ~74°F
Summer average ~76°F
Explore water temperatures
Where to stay near Sleepy Eye Lake
Planning a swim or lake trip? Compare cabins, lodges, and vacation rentals near Sleepy Eye Lake — live availability and prices. Switch the map to Satellite to see the lake and how close each stay is to the water.
Top-rated places to stay near Sleepy Eye Lake
Prices for Sep 4–6, 4 adults. Change dates on the map below.
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Frequently asked questions
What is the water temperature of Sleepy Eye Lake?
Sleepy Eye Lake typically sits around 69°F at the surface in September, from 96 EPA Water Quality Portal field readings (2017–2023). That is a typical value for the month, not a live reading.
When is Sleepy Eye Lake warmest?
Surface water at Sleepy Eye Lake is typically warmest in July, reaching about 81°F. Lake surface temperature lags air temperature by several weeks, so the warmest water usually arrives in mid-to-late summer even though the hottest air can come earlier.
Is Sleepy Eye Lake warm enough to swim?
At its typical summer peak of about 79°F, Sleepy Eye Lake rates as "comfortable" for swimming. Pleasant for swimming — the range most people find enjoyable without a wetsuit.
Where does this Sleepy Eye Lake water temperature data come from?
Every temperature on this page is a typical (climatological) value computed from real surface-water field readings collected by state and federal agencies and published through the EPA Water Quality Portal — 96 readings from 1 monitoring station between 2017 and 2023. They describe what is typical for each month, not the temperature right now.
About this data
Water temperatures are a climatology — the typical value for each month, averaged from real surface-water field readings collected by state and federal agencies and published through the EPA Water Quality Portal. They tell you what to expect, not the temperature at this moment. Actual conditions vary with recent weather, depth, and time of day.